The present invention relates to a write-once (information can be written once, thereafter it can only be reproduced) optical recording film, a method for manufacturing the same, an optical recording medium, a method for manufacturing the same, an information recording/reproducing apparatus using the same, a computer system using the same, and a video signal recording/reproducing system.
Recently, the amount of electronic information has risen dramatically, so that there is a need for the development of high-capacity low-cost optical information storage media. High-capacity low-cost optical information storage media are for example in high demand for recording video information of various formats and as supplemental storage media for computers. Most of the high-capacity optical information recording media that are currently under development use magnetic recording, optomagnetic recording or phase-change recording.
In magnetic recording, a super-thin layer of a metallic magnetic material is provided in a medium substrate, so that information is recorded by magnetizing the magnetic material by irradiation with magnetic force lines.
In optomagnetic recording, a magnetic chemisorptive thin film is heated partially to above the Curie temperature or the temperature compensation point, and information is written by extinguishing the coercivity of these portions and inverting the orientation of the magnetization into the direction of a magnetic recording field applied from outside.
In phase-change recording, a recording film made of a special alloy is irradiated with a laser beam, and information is recorded by switching the alloy between a crystalline state and an amorphous state.
However, when using any of these recording methods, the recording layer is formed by vacuum vapor deposition. Therefore, there is the problem that the manufacturing costs for these optical recording media are high.
Furthermore, with these methods, there is the problem that optical recording media that are compatible with various types of information recording/reproducing apparatuses cannot be manufactured easily.
In view of the above, it is a first object of the present invention to provide an optical recording film which an optical recording layer can be formed using an organic thin film, but without using vacuum vapor deposition, and a method for manufacturing the same.
It is a second object of the present invention to provide an inexpensive high-density write-once optical recording medium using this optical recording film.
It is a third object of the present invention to provide a computer system and a video signal recording/reproducing system using the write-once optical recording medium.
A first write-once optical recording film in accordance with the present invention includes:
a chemisorptive thin film with orienting properties fixed directly or through a primer layer to a substrate surface; and
a coating formed on a surface of the chemisorptive thin film;
wherein the coating has an initial molecule orientation attained by aligning a group of polymerizable molecules in a predetermined direction on the surface of the chemisorptive thin film, and polymerizing the polymerizable molecules to one another; and
wherein regions with changed initial molecule orientation and regions with unchanged initial molecule orientation of the coating are formed when selectively irradiating the coating with light that changes the initial molecule orientation, making optical information recording possible.
A first method for manufacturing a write-once optical recording film in accordance with the present invention includes:
forming a chemisorptive thin film on a substrate;
subjecting the chemisorptive thin film to an orientation treatment;
bringing a surface of the chemisorptive thin film in contact with polymerizable molecules by applying a solution in which the polymerizable molecules have been dissolved to the surface of the chemisorptive thin film, removing the solvent, and aligning a group of the polymerizable molecules in a predetermined direction at the surface of the chemisorptive thin film with the orientation regulating force of the chemisorptive thin film; and
forming a coating by bonding (e.g. polymerizing or crosslinking) the polymerizable molecules to one another.
In accordance with the present invention, a first optical recording medium comprising an optical recording layer on at least one surface of a medium substrate includes an optical recording film comprising:
a chemisorptive thin film with orienting properties fixed directly or through a primer layer to a substrate surface; and
a coating formed on a surface of the chemisorptive thin film;
wherein the coating has an initial molecule orientation attained by aligning a group of polymerizable molecules in a predetermined direction on the surface of the chemisorptive thin film, and polymerizing the polymerizable molecules to one another; and
wherein regions with changed initial molecule orientation and regions with unchanged initial molecule orientation of the coating are formed by selectively irradiating the coating with light that changes the initial molecule orientation, making optical information recording possible.
In accordance with the present invention, a first method for manufacturing an optical recording medium provided with a recording layer in which optical information can be recorded by changing an initial molecule orientation of a coating constituting the recording layer by selectively irradiating focused light, includes:
forming a chemisorptive thin film on at least one surface of a medium substrate;
subjecting the chemisorptive thin film to an orientation treatment;
bringing a surface of the chemisorptive thin film in contact with polymerizable molecules by applying a solution in which the polymerizable molecules have been dissolved to the surface of the chemisorptive thin film, removing the solvent, and aligning a group of the polymerizable molecules in a predetermined direction at the surface of the chemisorptive thin film with the orientation regulating force of the chemisorptive thin film; and
forming a coating by polymerizing the polymerizable molecules to one another.
In accordance with the present invention, a first method for optical recording on an optical recording medium provided with an optical recording layer on at least one surface of a substrate is provided,
wherein the optical recording layer comprises a chemisorptive thin film with orienting properties fixed directly or through a primer layer to the surface of the substrate, and a coating formed on a surface of the chemisorptive thin film;
wherein the coating has an initial molecule orientation attained by aligning a group of polymerizable molecules in a predetermined direction on the surface of the chemisorptive thin film, and polymerizing the polymerizable molecules to one another;
wherein regions with changed initial molecule orientation and regions with unchanged initial molecule orientation of the coating are formed when selectively irradiating the coating with light that changes the initial molecule orientation, thus recording optical information.
In accordance with the present invention, a first information recording/reproducing apparatus for recording and reproducing information on a write-once optical recording medium,
wherein the write-once optical recording medium is provided with an optical recording layer on at least one surface of a substrate;
wherein the optical recording layer comprises a chemisorptive thin film with orienting properties fixed directly or through a primer layer to the surface of the substrate, and a coating formed on a surface of the chemisorptive thin film;
wherein the coating has an initial molecule orientation attained by aligning a group of polymerizable molecules in a predetermined direction on the surface of the chemisorptive thin film, and polymerizing the polymerizable molecules to one another; and
wherein regions with changed initial molecule orientation and regions with unchanged initial molecule orientation of the coating can be formed by selectively irradiating the coating with light that changes the initial molecule orientation;
comprises:
a signal input/output portion;
a recording light emitting portion selectively emitting recording light for writing information elements by changing the initial molecule orientation of the chemisorptive thin film constituting the recording layer, in accordance with an information signal from the signal input/output portion;
an information recording portion including said optical recording medium, on which information is recorded by irradiating the recording light emitted from the recording light emitting portion;
a reference light emitting portion for emitting reference light that does not change the initial molecule orientation of the coating constituting the recording layer, used for reproduction of information recorded on the optical recording medium of the information recording portion;
an information element detecting portion which irradiates the reference light on the optical recording medium, detects with an optical sensor an intensity change of a polarized component of reflected light, transmitted light or scattered light of the reference light, due to differences in information elements, and outputs a predetermined electrical signal to the signal input/output portion, based on the detected results;
a position control driving portion, which shifts or rotates the optical recording medium in order to selectively irradiate the recording light and the reference light on predetermined positions of the optical recording medium; and
a control circuit portion for controlling the recording operation by coordinating the recording light emitting portion and the position control driving portion, and controlling the reproduction operation by coordinating the information element detecting portion and the position control driving portion.
A first computer system in accordance with the present invention includes:
an arithmetic processing device including a main memory;
an auxiliary recording device connected to the arithmetic processing device and serving as an auxiliary memory;
an input device connected to the arithmetic processing device;
an output device connected to the arithmetic processing device; and
a control device for controlling data communication between the devices;
wherein the auxiliary recording device is an information recording/reproducing device using an optical recording medium;
wherein the optical recording medium is a write-once optical recording medium provided with an optical recording layer on at least one surface of a substrate;
wherein the optical recording layer comprises a chemisorptive thin film with orienting properties fixed directly or through a primer layer to a surface of the substrate, and a coating formed on a surface of the chemisorptive thin film;
wherein the coating has an initial molecule orientation attained by aligning a group of polymerizable molecules in a predetermined direction on the surface of the chemisorptive thin film, and polymerizing the polymerizable molecules to one another; and
wherein regions with changed initial molecule orientation and regions with unchanged initial molecule orientation of the coating can be formed when selectively irradiating the coating with light that changes the initial molecule orientation;
the computer system comprising:
a signal input/output portion;
a recording light emitting portion selectively emitting recording light for writing information elements by changing and destroying the initial molecule orientation of the coating constituting the recording layer, in accordance with an information signal from the signal input/output portion;
an information recording portion including said optical recording medium, on which information is recorded by irradiating the recording light emitted from the recording light emitting portion;
a reference light emitting portion for emitting reference light that does not change the initial molecule orientation of the coating constituting the recording layer, used for reproduction of information recorded on the optical recording medium of the information recording portion;
an information element detecting portion which irradiates the reference light on the optical recording medium, detects with an optical sensor an intensity change of a polarized component of reflected light, transmitted light or scattered light of the reference light that has passed through a polarizer, due to differences in information elements, and outputs a predetermined electrical signal to the signal input/output portion, based on the detected results;
a position control driving portion, which shifts or rotates the optical recording medium in order to selectively irradiate the recording light and the reference light on predetermined positions of the optical recording medium; and
a control circuit portion for controlling the recording operation by coordinating the recording light emitting portion and the position control driving portion, and controlling the reproduction operation by coordinating the information element detecting portion and the position control driving portion.
In another computer system making use of an optical information storage medium, an improvement is that the optical information storage medium comprises the first write-once optical recording film in accordance with the present invention.
A first video signal recording/reproducing system in accordance with the present invention includes:
a video signal input/output control device controlling the input source and the output destination of a video signal;
a video recording/reproducing device connected to the video signal input/output control device;
a video output device connected to the video signal input/output control device; and
a control command input device for sending input/output control commands to the video signal input/output control device, connected to the video signal input/output control device;
wherein the video recording/reproducing device is an information recording/reproducing device using an optical recording medium;
wherein the optical recording medium is a write-once optical recording medium provided with an optical recording layer on at least one surface of a substrate;
wherein the optical recording layer comprises a chemisorptive thin film with orienting properties fixed directly or through a primer layer to a surface of the substrate, and a coating formed on a surface of the chemisorptive thin film;
wherein the coating has an initial molecule orientation attained by aligning a group of polymerizable molecules in a predetermined direction on the surface of the chemisorptive thin film, and polymerizing the polymerizable molecules to one another; and
wherein regions with changed initial molecule orientation and regions with unchanged initial molecule orientation of the coating can be formed when selectively irradiating the coating with light that changes the initial molecule orientation;
the video signal recording/reproducing system comprising:
a signal input/output portion;
a recording light emitting portion selectively emitting recording light for writing information elements by changing and destroying the initial molecule orientation of the coating constituting the recording layer, in accordance with an information signal from the signal input/output portion;
an information recording portion including said optical recording medium, on which information is recorded by irradiating the recording light emitted from the recording light emitting portion;
a reference light emitting portion for emitting reference light that does not change the initial molecule orientation of the coating constituting the recording layer, used for reproduction of information recorded on the optical recording medium of the information recording portion;
an information element detecting portion which irradiates the reference light on the optical recording medium, detects with an optical sensor an intensity change of a polarized component of reflected light, transmitted light or scattered light of the reference light that has passed through a polarizer, due to differences in information elements, and outputs a predetermined electrical signal to the signal input/output portion, based on the detected results;
a position control driving portion, which shifts or rotates the optical recording medium in order to selectively irradiate the recording light and the reference light on predetermined positions of the optical recording medium; and
a control circuit portion for controlling the recording operation by coordinating the recording light emitting portion and the position control driving portion, and controlling the reproduction operation by coordinating the information element detecting portion and the position control driving portion.
In another video signal recording/reproducing system making use of an optical information storage medium, an improvement is that the optical information storage medium comprises the first write-once optical recording film in accordance with the present invention.
In a second aspect, a write-once optical recording film in accordance with the present invention comprises:
a thin film made of chemisorptive molecules fixed directly or through a primer layer to a substrate surface by covalent bonding;
wherein optical information can be recorded on the thin film by irradiating light to degrade the molecules at the irradiated portions.
A second method for manufacturing a write-once optical recording film in accordance with the present invention, which comprises a thin film made of chemisorptive molecules fixed by covalent bonds directly or through a primer layer to a substrate surface, wherein optical information can be recorded on the thin film by irradiating light to degrade the molecules at the irradiated portions;
comprises bringing a chemisorptive compound including a chemisorptive group and a functional group that degrades when irradiated with light in contact with a substrate or a primer layer including active hydrogen at its surface to cause an elimination reaction between the chemisorptive group and the active hydrogen, and thereby fixing the chemisorptive compound by covalent bonding directly or through a primer layer to a substrate surface.
A second write-once optical recording medium including a write-once optical recording film comprises a substrate and a thin film made of chemisorptive molecules fixed by covalent bonds directly or through a primer layer to one or both sides of the substrate, in which optical information can be recorded;
wherein the optical recording film can be optically recorded by irradiating light to degrade the molecules at the irradiated portions.
A second method for manufacturing a write-once optical recording medium, which comprises a substrate and a thin film made of chemisorptive molecules fixed by covalent bonds directly or through a primer layer to one or both sides of the substrate, wherein optical information can be recorded in the thin film by irradiating light to degrade the molecules at the irradiated portions;
comprises bringing a chemisorptive compound including a chemisorptive group and a functional group that degrades when irradiated with light in contact with a substrate or a primer layer including active hydrogen at its surface to cause an elimination reaction between the chemisorptive group and the active hydrogen, and fixing the chemisorptive compound by covalent bonding directly or through a primer layer to the substrate surface.
A second method for recording/reproducing information on a write-once optical recording medium, which comprises a substrate and a thin film made of chemisorptive molecules fixed by covalent bonds directly or through a primer layer to one or both sides of the substrate, wherein optical information can be recorded in the thin film by irradiating light to degrade the molecules at the irradiated portions, comprises:
a recording step of recording information by irradiating recording light on the optical recording film to degrade the irradiated portions into degraded portions, and by combining the degraded portions and non-degraded portions; and
a reproduction step of reproducing information by irradiating reproduction light on the degraded portions and the non-degraded portions and detecting a difference in the optical intensity after the light has reached the degraded portions and the non-degraded portions.
A second apparatus for recording/reproducing information on a write-once optical recording medium, which comprises a substrate and a thin film made of chemisorptive molecules fixed by covalent bonds directly or through a primer layer to one or both sides of the substrate, wherein optical information can be recorded in the thin film by irradiating light to degrade the molecules at the irradiated portions, comprises:
a signal input/output means for input/output of information signals of information converted into electrical signals and operation command signals to/from an external device;
a recording light irradiation means for irradiating recording light in order to degrade the molecules constituting the optical recording film, in accordance with an information signal from the signal input/output means;
a reproduction light irradiation means for irradiating reproduction light that does not degrade the molecules constituting the optical recording film, used for reproduction of information recorded on the optical recording medium of the information recording portion;
an information element detecting means which irradiates the reference light on the optical recording medium, detects an intensity of reflected light or transmitted light after the reproduction light has reached the optical recording film, and outputs a predetermined electrical signal to the signal input/output means, based on the detected results;
an optical recording medium driving means for irradiating the recording light or the reproduction light onto a predetermined position of the optical recording film; and
a control circuit means for controlling the recording operation by coordinating the recording light irradiation means and the optical recording medium driving means, and controlling the reproduction operation by coordinating the reproduction light irradiation means, the optical recording medium driving means and the information element detecting means.